Fix dangerous parsing of Omero importer return values

[wow-such-code]

etl-scripts/drop-boxes/register-omero-metadata/backendinterface.py

Line 147 in c9b8cf4

image_ids = fist_line[6:].split(',')

This code is also used in two different methods. It might makes sense to write a new method to do this.

[sven1103]

@luiskuhn can you please address this in your current refactoring work and close it afterwards?